L.4 Flashcards
motility of git
- mastication “ chewing “
- swallowing “deglutition “
- gastric motility & vomiting
- motility of small intestine
- motility of the colon
process of breakdown of large food into small pieces
mastication
mastication occurs in mouth by combined action of
- jaws
- teeth
- masticatory muscles
- tongue & cheeks
mastication start ——- but it maintained by —— created by the presence of food in the buccal cavity
- voluntary
- reflexes
location of the mastication center is in
pons and medulla
passage of food from the mouth to stomach
deglutition
deglutition center present in
medulla
phases of deglutition
- oral phase
- pharyngeal phase
- esophageal phase
name of voluntary phase of deglutition
oral phase
Steps of oral phase
Tip of tongue is raised & base of tongue is depressed ➡️ backward to the pharynx
Steps of oral phase
tongue is raised and the base of the tongue is depressed ➡️ backward to the pharynx
Passage of food through the pharynx, name of this stage 
Pharyngeal stage and it’s involuntary
Common pathway of both food and air passage
Pharynx
Food is directed towards esophagus by two effects which is
- Protective reflexes
- Pharyngeal peristalsis
Steps of the protective reflexes protection the airway
- Elevation of soft palate
- Contraction of myelohyoid muscles “ Keep the tongue near the hard palate”
- Elevation of larynx against epiglottis
- Approximation of the vocal chords
- Reflex Inhibition of respiratory centre
Name the stage that prevent regurgitation of food into posterior nasal cavity
Elevation of soft palate
Name the stage that prevent regurgitation of food into the buccal cavity
Contraction of myelohyoid muscles
Name the stages that prevent passage of food in trachea
- elivation of larynx against epiglottis 
- approximation of vocal cord
- Inhibition of respiration
Approximation of vocal cord will close the 
Glottis “ opening between vocal folds “
Steps of pharyngeal peristalsis
Contract of superior pharyngeal muscle ➡️ rapid peristalsis movement which passes downwards through pharynx ➡️
Pushing of bolus into relaxed esophagus
Peristaltic movment of esophagus push food to ——- and —— accelerate the movement
- Stomach
- Gravity
All the motility stages of git are involuntary except
Oral stage
Lower esophageal sphincter tonically contracted to prevent
Reflux of gastric acid
Lower esophageal sphincter relaxes during
Swallowing to allow passage of food
Lower esophageal sphincter is a ———
Sphincter
Physiological
Tone of lower esophageal sphincter (LES) is under neural control:
- Acetylcholine released from vagus —> Contraction of LES .
- Nitric oxide ,vasoactive intestinal peptide —> Relaxation of LES.
